[Elecraft] off topic-CPUs

[John J. McDonough]

----- Original Message -----
From: "John J. McDonough" <wb8rcr@arrl.net>
Subject: Re: [Elecraft] off topic-CPUs


> I don't think I've ever seen a computer monitor with composite inputs

I should have said, in recent years.  This was common in the early 80's,
and practically the only way it was done in the 70's, at least for color.
But the VGA display, rapidly followed by the XGA and Super-VGA displays made
this untenable.  At the 75 Hz refresh rate minimum required by Swedish law
at the time (and really, you need at least 60 to be bearable) that's over 2
million dots per second.  Since those dots need to have reasonably square
edges, you are past the 6 MHz bandwidth of a TV signal even at 640x480
(VGA).  At the 1024x768 XGA/Super-VGA you are way past the available
bandwidth of a composite signal.

I don't know that other countries ever enacted refresh rate laws like
Sweden, but it was a moot point since all the manufacturers quickly followed
the Swedish standards -  in the mid 80's it became a big selling point.

72/73 de WB8RCR    http://www.qsl.net/wb8rcr
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